Few At-Risk Women Elect to Use Tamoxifen to Prevent Breast Cancer

Women at risk for breast cancer are unwilling to accept the potential harms of tamoxifen in order to reduce their chances of breast cancer, say researchers who published their study in Breast Cancer Research and Treatment (2009 Nov 12 [Epub ahead of print]).

The study’s authors explained that although tamoxifen, a primary prophylaxis for women at increased risk of breast cancer, reduces primary breast cancer incidence, the treatment causes serious side effects.

To determine a woman’s preferences for taking tamoxifen, researchers recruited 632 women with increased breast cancer risk who viewed a tailored decision aid (DA) that informed them about their 5-year risk of breast cancer and presented individually-tailored content depicting the risk and benefits of tamoxifen prophylaxis. The study measured the participant’s behavioral intentions, knowledge, and perceived risks and benefits of tamoxifen.

Researchers reported that after viewing the DA, 28.8% of participants indicated they were likely to seek more information about tamoxifen and 29.5% indicated that they were likely to talk to their physician about tamoxifen. However, only 5.8% of participants reported that they were likely to take tamoxifen within the next year.

“The results demonstrated that when women are informed of their potential risks and benefits in the context of a computerized decision-aid, few seemed interested in tamoxifen,” the authors stated. The team found that women’s reluctance was due to concerns about side effects and the belief that the risks outweighed the benefits.

“Our participants’ lack of interest in tamoxifen does not mean that our DA failed. The DA was not designed to convince women to take tamoxifen,” the researchers explained. “It was designed to neutrally present risk and benefit information, so that participants could decide, for themselves or with their doctors, whether tamoxifen was a good option.”